4 ms·

The use case for 10BASE-T1S isn't quite clear to me. I get that you can do multidrop ethernet, which would simplify things a lot; no need to add switches or dai

The use case for 10BASE-T1S isn't quite clear to me. I get that you can do multidrop ethernet, which would simplify things a lot; no need to add switches or daisy chain anymore. And it's also not too slow, and you only need two wires. But are microcontrollers with ethernet common? How cheap are they? A MAC needs a lot of pins compared to CAN which will increase footprint. And to really take full advantage of ethernet, you need a good networking stack and a solid set of utilities and applications on top. So Linux is the way to go in that case. But then you need a big processor with external RAM, eMMC, PMIC, several layer board, and don't forget a couple of Linux weirdos (speaking as one) who can actually develop in that environment. A lot of embedded guys can understand CAN pretty easily; show them gRPC and their heads may explode. So I guess the use case is: embedded system with a lot of Linux boards that don't need that much bandwidth? Does that accurately reflect the architecture of a modern car?

bsder 5y ago
> But are microcontrollers with ethernet common? How cheap are they? Define "common". However, they are available. I see some right around $4 from ST. > A MAC needs a lot of pins compared to CAN which will increase footprint. Normally the pins on the connector are far more critical than the pins on the microcontroller. RMII takes up 9 pins on the microcontroller. > And to really take full advantage of ethernet, you need a good networking stack and a solid set of utilities and applications on top. So Linux is the way to go in that case. But then you need a big processor with external RAM, eMMC, PMIC, several layer board, and don't forget a couple of Linux weirdos (speaking as one) who can actually develop in that environment. A lot of embedded guys can understand CAN pretty easily; show them gRPC and their heads may explode. You are WAY too high-level. UDP works just fine for a lot of applications and takes next to nothing in terms of resources. And TCP doesn't require as much resource as you think (remember TCP dates back to the 1980s when memory was scarce). Even straight HTTP isn't too bad. The biggest problem is HTTPS. That invokes a whole crapload of overhead.

bsder 5y ago

> But are microcontrollers with ethernet common? How cheap are they? Define "common". However, they are available. I see some right around $4 from ST. > A MAC needs a lot of pins compared to CAN which will increase footprint. Normally the pins on the connector are far more critical than the pins on the microcontroller. RMII takes up 9 pins on the microcontroller. > And to really take full advantage of ethernet, you need a good networking stack and a solid set of utilities and applications on top. So Linux is the way to go in that case. But then you need a big processor with external RAM, eMMC, PMIC, several layer board, and don't forget a couple of Linux weirdos (speaking as one) who can actually develop in that environment. A lot of embedded guys can understand CAN pretty easily; show them gRPC and their heads may explode. You are WAY too high-level. UDP works just fine for a lot of applications and takes next to nothing in terms of resources. And TCP doesn't require as much resource as you think (remember TCP dates back to the 1980s when memory was scarce). Even straight HTTP isn't too bad. The biggest problem is HTTPS. That invokes a whole crapload of overhead.